Manufacture of finned tubing



June 11, 1935 E. A DEV VALD MANUFACTURE OF FINNED TUBING Filed June 25,1932 7 Sheets-Sheet 1 'l V TOR MZ 2 ATTORN EYS June 11, 1935. v w D2,004,388

MANUFACTURE OF FINNED TUBING Filed June 25, 1932 7 Sheets-Sheet 2!NVENTOR Q M4 M 7 BY ATTORNEYS June 11, 1935. E, ALDEwALD 2,004,388

MANUFACTURE OF FINNED TUBING Filed June '25, 1932 7 Sheets-Sheet 3INVENTOR ATTORNEYS June 11, 1935.

EA. DEWALD MANUFACTURE OF FINNED TUBING Filed June 25, 1932 7Sheets-Shed 4 2 INVENTOR ATTO R N EYS June 11, 1935. E. A. DEWALD I F-MANUFACTURE OF FINNED TUBING Filed June 25, 1932 '7 Sheets-Sheet 5 2 2INVENTOR ATTORNEYS June 11, 1935. E. A. DEWALD MANUFACTURE OF FINNEDTUBING Filed June 25, 1952 7 Sheets-Sheet 6 4 *1 INVENTOR 0 I g IATTORNEYS June 11, 1935. E. A. DEWALD MANUFACTURE OF FINNED TUBING FiledJune 25, 1952 7 Sheets-Sheet 7 WN I 3 2 INVENTOR ATTORNEYS Patented June11, 1935 Edward A. Dewald, Massillon,

The Griscom-Russell Company,

Ohio, assignor to New York,

N. Y., a corporation of Delaware Application June 25, 1932, Serial No.619,215

13 Claims.

This invention relates to the manufacture of finned tubing and comprisesimproved apparatus for making this product. The finned tubing comprisesa metal tube having secured to the external surface thereof a thin metalfin in the form of a helix. Such finned tubing is of great utility inthe manufacture of heat exchangers. This application is a continuationin part of my copending application, Serial Number 555,718, filed August7, 1931.

According to one embodiment of my invention a preformed helical coil ofmetal ribbon is progressively secured to a metal tube inserted into thepreformed coil. A method and apparatus for coiling the ribbon aredescribed and claimed in my copending application Serial Number 403,193,filed October 29, 1929. After the coil of metal ribbon has been formedit is preferably annealed and then a metal tube is inserted into thecoil and the coil is progressively secured to the tube. One end of thecoiled metal ribbon may be secured to the tube near one end thereof, agroove is formed in the surface of the tube, the tube is turned to drawthe coil progressively into the groove, and the ribbon is then anchoredin the groove by crimping the edges of the same into firm contact withthe lower side edges of the metal ribbon. My improved apparatus forperforming this operation comprises a machine of the lathe type havingadjustable tool heads, one of which carries a roughening roll and ascoring tool and the other of which carries a pair of lead rolls forguiding the metal ribbon into the groove formed by the scoring tool, anda pair of knurling rolls for crimping the edges of the groove into firmcontact with the lower edge of the ribbon. These several rolls and thescoring tool are independently adjustable and the tool heads are mountedso that the lead screw of the lathe causesthem to advance along the tubefrom one end thereof to the other. The tube is rotated with respect tothe tool heads and the precoiled ribbon is thus progressively anchoredto the tube.

According to another embodiment of my invention a metal ribbon iswithdrawn from a reel, or other suitable source of supply, and wounddirectly onto the tube in the form of a helix, the ribbon being anchoredto the tube as the helix is formed.

The various objects and advantages of my in vention will be moreapparent upon considering the following detailed description of certainembodiments thereof which description applies to the apparatus shown inthe accompanying drawings in which apparatus shown in Fig. 5 is alongitudinal section view of a por- 1 tion of the tailstock and of anexpansible collet secured to the headstock spindle;

Fig. 6 is an enlarged side elevation of the expansible collet;

Fig. 7 is a transverse section view taken on line. 15

11 of Fig. 6;

Fig. 8 is a transverse section paratus shown in Fig. 2, Fig. 8 line 8-8of Fig. 2;

view of the apbeing taken on Fig. 9 is an end elevation of the toolheads, taken 20 on line 9-9 of Fig. 2;

Fig. 10 is a longitudinal section view of the tool heads taken on linel0lfl of Fig. 8;

Fig. 11 is a diagonal section Vk'W of the tool heads taken on line Il-Hof Pill. 14:

Fig. 12 is a diagonal section vlu" of the tool heads taken on line l2 l2of Fig. 14;

Fig. 13 is a transverse section view showing the clip for securing aportion of the metal ribbon to the tube, taken on line I 3-43 of Fig.10;

Fig. 14 is an enlarged elevation of the tool head shown in Fig. 4;

Fig. 15 is a longitudinal section view of one of the tool heads, takenon line Iii-I5 of Fig. 14;

Fig. 16 is a transverse section view of one of the tool heads taken online l6-l6 of Fig. 14;

Fig. 17 is an enlarged perspective view of one of the ribbon guidesshown in Figs. 14 and 16;

Fig. 18 is a fragmentary side elevation of another embodiment of myinvention comprising apparatus for simultaneously coiling the metalribbon and applying the same to the tube;

Fig. 19 is an end elevation of the tool heads shown in Fig. 18, the tubebeing shown in section;

Fig. 20 is a longitudinal section view of one of the tool heads shown inFig. 19, taken on line 20-20 of Fig. 19;

Fig. 21 is a plan view of part of the adjusting mechanism forming a partof the apparatus 5 shown in Fig. 20;

Fig. 22 is a side elevation, partly in section, of thefinned tube,illustrating the method of applying a precoiled metal ribbon to thetube;

Fig. 23 is an enlarged fragmentary section view product being shown inFig. 22. In Fig. 22 I have illustrated a tube of copper, admiraltymetal, or the like, and a helical coil of metal ribbon 2, a portion ofwhich is shown anchored to the tube The operation consists of firsttoughening the surface of the tube as illustrated at3, then forming ahelical groove as shown at 4, whereupon the precoiled metal ribbon isfed into the groove and the edges of the groove are then crimped asshown at 5 to firmly anchor the inner edge of the ribbon to the tube.The precoiled ribbon may be formed in any suitable manner but I preferto employ the process covered by my aforesaid pending application SerialNo. 403,193, filed October 29, 1929. The precoiled ribbon is preferablyannealed before it is secured -to the tube.

Referring to Figs. 1 and 2 I have illustrated a machine of the lathetype having supports 6 and 1, a bed 8 and a motor 9 for driving aheadstock spindle l through gears H and I2. The spindle in is geared toa lead screw 53 through a train of gears 94. Two cooperating tool headsl5 and H5 are mounted on the lathe bed and the tube 5 is carried betweenthe headstock spindle l0 and the tailstock In. The tool heads l5 and i6are mounted on brackets l1 and |8, respectively, carried by a commoncarriage plate l9 mounted on the bed The brackets i1 and I8 are slidablymounted on the carriage plate l9 and are adjustable toward and away fromeach other in the usual manner by a cross feed screw 20 connected to ahand crank l. The carriage plate I9 is provided with a bracket 22slidably mounted on a rod 23 (see Fig. 8). The bracket 22 carries alever 24 having a handle 25 and a threaded shoe 26 engaging the leadscrew 13. It will be understood that when the handle 25 is in itslowered position the threaded shoe 26 engages the lead screw l3 and thetool heads then move along the bed as the lead screw 63 is rotated bythe motor.

The tailstock shown in Figs. 1, 2 and 5 comprises a frame 21 adapted tobe anchored to the bed by means of a set screw 28. The frame 21 carriesa sleeve 29 normally forced toward the headstock spindle ill by a spring30.' A shaft 3| is rotatably mounted in the sleeve 29 by means ofsuitable bearings 32. The shaft 3| carries a projection 33 adapted toenter the end of the tube on which the metal ribbon is to be secured.The end of the shaft 3| forms an abutment for the end of the tube asshown at 34.

The headstock spindle I0 is provided with an improved expansible collet35 as best illustrated in Figs. 5, 6 and 7. This expansiblecollet.comprises a sleeve 36 having a split end provided with knurled surfaces31 adapted to engage the inside of the adjacent end of the tube and anexpansion wedge member 38 fits in the end of this split sleeve 36 and iscarried bya rod 39 secured to a sliding block 46. I, This sliding blockis mounted within a second sleeve 4| which has a screwthreadedconnection 42 with the headstock spindle Hi. The sleeve 4| is providedwith diametrically opposed slots and the pin 43 passes through thesliding block 40 and projects through these slots in the sleeve 4|. Theends of the pin are mounted in a ring 44 surrounding the sleeve 4| andmounted within an annular channel in a second ring 45. This outer ring45 has a plurality of projections 46 adapted 'to be engaged by ashifting lever or yoke 41, and it will be understood that by forcingthis outer ring to the left as shown Figs. 8, 9 and 10) having a flange50 bolted to the bracket l8. The support 49 carries a grooving tool 5|and a roughening roll 52. The grooving tool 5| comprises a cuttingor'grooving member proper 53 and a tool holder 54 to which the tool 53is secured by a set screw 55. The tool holder 5| is provided with slotsfor receiving bolts 56 and 51. These. bolts are carried by threadedsleeves 58 and 59 mounted in the support 49. An adjusting screw 6|] ismounted in' the flange 5|] with the head 6| of the adjusting screwengaging the end of the tool holder 54. By loosening the nuts on thebolts 56 and 51 the position of the tool holder 54 with respect to thesupport 39 can be adjusted by manipulating the adjusting screw 69. Thisadjustment is independent of all other adjustments for the several rollsand accordingly the grooving tool can be adjusted with respect to theseveral rolls to bring it into proper position to perform its functionof scoring a groove in the surface of the tube The roughening vroll 52is mounted in a holder 62 and this holder is mounted on the support 49in exactly the same manner as the grooving tool holder. The holder 62 isslotted and normally clamped against the support 49 by bolts 63 and 64and when it is necessary to adjust the position of the roughening roll52 the nuts on the bolts 63 and 64 are loosened and an adjusting screw65 mounted in the flange 5|! and abutting against the end of the holder62 is manipulated to adjust the position of the holder with respect tothe support 49. The flange 50 is properly centered on the bracket 18 bymeans of a projection 66 fitting into a corresponding opening in thebracket.

The tool head I5 comprises a support 61 having a flange t8 secured tothe bracket H by bolts 69 and 18, the flange being properly centered onthe bracket by virtue of a projection 11 fitting into a correspondingrecess in the face of the bracket. The tool head l5 carried the leadrolls 12 and 13 and the knurling rolls 14 and 15. The lead roll 12 isrotatably mounted in a holder 16 and this holder is normally clampedagainst the support 61 by bolts 11 and 18. These bolts pass throughslots in the holder 16 and through threaded sleeves 19 and 80 carried bythe support 61. An adjusting screw 8| is provided in the support 61 andhas a tapered end engaging a corner of the holder 16. Accordingly, theposition of the roll 12 can be adjusted by loosening the nuts on thebolts 11 and 18 and manipulating the adjusting screw 1|.

The lead roll 13 is rotatably mounted in a holder 82 and this holder isnormally clamped against a side plate 83 by means of bolts 84 and 85passing through slots in the holder 82 and through threaded sleeves 86and 81 mounted in the side plate 83. An adjusting screw 88 is providedin the side plate 83 and whenever it is necessary to adjust the leadroll I3 the nuts on the bolts I4 and I5 are loosened and the adjustingscrew 88 turned in the desired direction to provide for the necessarydisplacement of the holder 82 with respect to the side plate 83. Thetapered end of the adjusting screw 88 engages the rear corner of theholder 82 and is therefore adapted to slide the holder 82 along the sideplate 83. The side plate 83 iscarried on a shaft 89 having a handle 98at one end thereof and a screwthreaded portion 9| at the other endthereof.

- The screw-threaded portion engages a threaded hole inthe support 81.which is shown at 92 in Fig. 15, are provided on the side plate 83 andfit into corresponding recesses in the support 61. Adjusting screws 94and 94' are provided in the support 61 and engage the ends of theprojections 92 (see Fig. 14). A second pair of lugs, one of which isshown at 93, in Fig. 15, are provided on the side plate 83 and fit intocorresponding recesses in the support 81. Adjusting screws 95 and 95'are provided in the support 61 and engage the ends of the projections 93(see Fig. 14). It will be understood that the distance between the leadrolls 'I2 and I3 can be adjusted by manipulating the handle 98 on theshaft 89, and the adjusting screw 94, 94', 95 and 95. For example, ifthe lead rolls I2 and I3 need to be separated to accommodate a thickerribbon, then the shaft 89 can be turned by means of the handle 98 toseparate the side plate 83 from the support 81 to thus bring the leadrolls into the proper relative positions. The screws 94, 94',v

95 and 95' can then be tightened against the projections 92 and 93 tohold the side plate 83 and the support 61 in the proper position.

The knurling roll I4 is rotatably mounted in a holder 98 (see Figs. 15and 16) and this holder is normally clamped against the inner face ofthe support 61 by bolts 91 and 98 (see Fig. 14). These bolts passthrough slots in the holder 96 and through threaded sleeves 99 and I88mounted in the support 61. In like manner the knurling roll I5 isrotatably mounted in a holder IN and this holder is normally clampedagainst the in her face of the side plate 83 by bolts I82 and I83. Thesebolts pass through slots in the holder I8I and through threaded sleevesI84 and I85 mounted in the side plate 83. The adjustment of the roll 15is secured by loosening the nuts on the bolts I82 and I83 and thenmanipulating an adjusting screw I86 (see Figs. 14 and 16). In likemanner the position of the knurling roll I4 can be adjusted by firstloosening the nuts on the bolts 91 and 98 and then manipulating theadjusting screw I 81.

A pair of ribbon guides I88 and I 89 serve to guide the ribbon into thegroove in the surface of the tube. The guide I88 is fastened to thesupport 61 by a screw H8 and the guide I89 is fastened to the side plate83 by a screw I I I. Each of these guides is of the form illustrated inFig. 17 where I have shown the ribbon guide I89.

' This guide comprises a support II2 having a slot therein to receivethe screw. A shank on the end of this support is provided with a curvedsurface II3 to accommodate the lead roll I3 and a corresponding curvedsurface I I 4 to accommodate the knurling roll I5. There is also acurved surface II 5 at the end of this shank machined to conform withthe curvature of the tube I. These ribbon guides are easily removableand can be replaced by similar guides having the surface I I5 shaped toconform with the curvature of tubes of different sizes.

A pair of lugs, one of- In Fig. 13 I have illustrated a spring clip H6which can be used for the purpose of holding one edge of the ribbon 2 incontact with the tube I until the operation of the machine has proceededto a point where a portionof theribbon is embedded in the surface of thetube. Thereafter it isnot necessary to use the clip. 1

The apparatus illustrated in Figs. 1 to 17-inclusive is particularlysuitable for applying to a tube a preformed helical coil of thin metalribbon. This coil of metal ribbon, whether of copper or other ductilemetal, is first placed on the tube and the tube is then mounted betweenthe headstock spindle I8 and the tailstock with the expansible colletgripping the end of the tube adjacent the headstock. The spring clip II6 is then applied to the end of the ribbon and the machine is started.The roughing roll 52 first roughens the surface of the tube tofacilitate the subsequent scoring or grooving operation. The stationarygrooving tool 53 presses the groove into the surface of the tube, thegroove having raised edges and being of suflicient width to accommodatethe edge of the metal ribbon which is fed into the groove by therotation of the tube and the guiding action of the lead rolls I2 and I3and the ribbon guides I88 and I89. The knurling rolls I4 and I5 thencrimp the edges of the groove against the sides of the ribbon to anchorthe inner edge of the ribbon firmly to the tube. As this operationproceeds the tool heads move along the bed due to the action of the leadscrew and accordingly the coiled ribbon is anchored to the tube in theform of a helix. The utility of the apparatus is due in large measure tothe fact that the tube is adequately supported at all times during theoperation of applying the fin to the tube.

The grooving tool and the lead rolls and knurling scribed. Thisapparatus is however modified to the extent necessary to handle a ribbonthat is not previously coiled. In Fig. 18 I have illustrated the lathebed 8, the lead screw I3, the tailstock 21 and the headstock spindle I8.The tube I is mounted between the headstock spindle I8 and the tailstockin the manner previously described. A tool carriage plate I9 is providedwith a support I II that carries a spool of metal ribbon .II8. Thismetal ribbon is fed to the tool heads I6 and IT. The construction of thetool head I6 is similar in all respects with the construction of thetool head I6 previousy described, the same reference characters havingbeen applied. The construction of the tool head I I is similar to thatof the tool head I1 previously described except for the provision of atension roll adapted to engage the outer edge of the ribbon to assist inthe operationof coiling the ribbon 2 around the tube I, and one of thelead rolls is cut away to accommodate the tension roll. I havedesignated this lead roll by the reference character I3 and by referringto Fig. 20 it will be noted that'the tension roll I I9 is mounted in thespace provided by this cutaway portion of the lead roll I3. The tensionroll H9 is rotatably mounted in an eccentric bearing I28. An adjustingarm I2I is secured to this eccentric bearing and can be moved to any oneof a number of adjusted positions determined by the teeth I22-on anadjustment plate secured to the side plate 83 by means of a screw I24. 7

The manner of applying ribbon to the tube by means of the apparatusshown in Figs. 18 to 21 inclusive is illustrated in Fig. 24 which showsthe straight ribbon 2 being fed into the groove formed in the tube I. Asthe tube l is rotated in the manner previously described the rougheningroll roughens the surface of the tube as indicated at 3, the groovingtool then forms a groove 4, the ribbon is fed into the groove andthereafter the edges of the groove are crimped against the sides of theribbon to anchor the same to the tube. The joint formed between theribbon and the tube is best illustrated in Fig. 23 which shows the edgesof the groove crimped against the sides of the inner edge of the ribbon2 and where the ribbon is of ductile material this action may serve tocompress the ribbon to such an extent that it is somewhat narrower atthis point than is the case with that portion of the ribbon that is notembedded in the surface of the tube.

It is to be understood that my invention is not limited to theparticular embodiments illustrated and described but includes suchmodifications thereof as fall within the scope of the appended claims.

I claim:-

1. A machine of the type described, comprising means for supporting ametal tube, a blunt scoring tool, means for rotating the tube withrespect to the scoring tool, whereby a groove is formed in the tube,means for feeding a metal fin into the groove, and means for crimpingthe groove edges to cause the same to grip the fin.

2. A machine of the type described, comprising means for supporting ametal tube, means for roughening a portion of the outer surface of thetube, a blunt scoring tool, means for rotating the tube with respect tothe scoring tool, whereby a groove is formed in the roughened portion ofthe tube, means for feeding a metal fin edgewise into the groove, andmeans for crimping the groove edges to cause the same to grip the fin.

3. A machine of the type described, comprising means for supporting ametal tube, means for roughening a portion of the outer surface of thetube, means for forming a groove in the roughened portion of the tube,means for feeding a metal fin edgewise into the groove, and means forcrimping the groove edges to cause the same to grip the fin, saidroughening means comprising a rotatable wheel having a rough surfaceadapted to engage the tube.

4. A machine of the type described, comprising means for supporting ametal tube, meansfor forming a groove in the tube, rotatable guidingmeans for guiding a metal fin into the groove, rotatable crimping meansfor crimping the edges of the groove to cause the same to grip the fin,andstati-onary fin guiding means mounted between the rotating guidingand crimping means.

5. A machine of the type described, comprising means for supporting ametal tube, means for forming a groove in the tube, rotatable guidingmeans for guiding a metal fin into the groove, rotatable crimping meansfor crimping the edges of the groove to cause the same to grip the fin,and stationary fin guiding means mounted between the rotating guidingand crimping means, said stationary guiding means comprising a pair ofspaced apart members, and means for adjusting at least one of saidmembers to vary the space therebetween.

6. A machine of the type described, comprising a pair of tool heads,means for adjusting said heads toward and away from the tube to beoperated upon, a pair of rolls mounted on one of said heads in angularspaced relation about the center of the tube, means for independentlyadjusting said rolls on the heads supporting the same, a grooving tooland a roughening roll mounted on the other tool head, and means forindependently adjusting said tool and roll thereon.

'7. A machine of the type described, compris-' inga pair of tool heads,means for adjusting said heads towards and away from the tube to beoperated upon, guiding and crimping rolls mounted on one of said heads,and. roughening and scoring means mounted on the other of said heads.

8. A machine of the type described, comprising a pair of tool heads,means for adjusting said heads toward and away from the tube to beoperated upon, guiding and crimping rolls mounted on one of said heads,and roughening and scoring means mounted on the other of said heads, thesaid rolls and the roughening and scoring means being each independentlyadjustable on said heads.

9. In a machine of the type described, a tool head comprising a pair ofsupporting plates, means for adjusting said plates toward and away fromeach other, a bar carried by each of said plates, a tool mounted on eachof said bars, and means for independently adjusting said bars on saidplates.

10. A machine of the type described, comprising means for supporting ametal tube, means for forming a helical groove about the tube, a springclip for temporarily clamping a portion of a metal ribbon to the tube,and means for progressively anchoring said ribbon in the groove.

11. A machine of the type described, comprising means for forming agroove in said tube, means for guiding a metal ribbon edgewise into saidgroove, a tension roll for engaging the outer edge of the ribbon, aneccentric bearing for said tension roll, means for adjusting the angularposition of said bearing to vary the position of the tension roll withrespect to the tube, and means for anchoring the ribbon in the groove.

12. A machine of the type described, comprising means for supporting ametal tube, means for forming a groove in said tube, a pair of leadrolls for guiding a metal ribbon into the groove, a bearing projectingthrough one of said lead rolls, a tension roll eccentrically mounted insaid bearing and disposed between said lead rolls, means for adjustingthe angular position of said bearing, and means for anchoring the ribbonin the groove.

13. A machine of the type described, comprising means for supporting ametal tube, blunt scoring means, means for moving the tube with respectto said scoring means whereby said scoring means displaces a portion ofthe metal of the tube to form a groove having raised edges, means forfeeding a metal fin into the groove, and means for crimping the grooveedges to cause the same to grip the fin.

EDWARD A. DEWALD.

